双螺杆挤压法生产小米方便粥的工艺优化

The process optimization of millet instant porridge production with twin-screw extruder

【目的】以小米粉为主要原料复配脱脂大豆粉,用双螺杆挤压法开发升糖指数较低的方便粥,并优化其加工工艺。【方法】根据FAO/WHO标准模式确定脱脂大豆粉复配比例。在单因素试验基础上运用Box-Behnken Design(BBD)方法设计优化试验,研究挤压温度、螺杆转速、物料水分含量和烤炉温度对方便粥品质的影响,最终确定最优加工工艺条件。【结果】脱脂大豆粉添加量(w)为30%时,小米粉与其互补后必需氨基酸评分均大于1,符合FAO/WHO标准模式。最佳加工工艺条件为:挤压温度145℃,螺杆转速220 r/min,水分含量35%(w)。以优化出的工艺条件进行试验,获得糊化度较高(86.72%)、升糖指数较低(63.21)、复水率较高(305%)并且感官评分较高(93分)的小米方便粥产品。【结论】工艺条件对方便粥的理化性质和食用品质影响显著,其变化规律可为其他相关产品的开发提供理论依据。

【Objective】To develop a kind of instant porridge with a lower glycemic index by the twin-screw extrusion processing using millet flour as the main raw material to mix with defatted soybean flour,and optimize the processing technology.【Method】The mix ratio of defatted soybean flour was determined according to the FAO/WHO standard model.Based on the single-factor test,the Box-Behnken Design(BBD)method was used to design and optimize the experiment.The effects of extrusion temperature,screw speed,material moisture content,and oven temperature on the quality of instant porridge were studied to finally determine the optimal processing technology condition.【Result】When the addition amount of defatted soybean flour was 30%(w),the essential amino acid scores were all greater than one after complementing with millet flour,which complied with the FAO/WHO standard mode.The optimal processing conditions were the extrusion temperature of 145℃,the screw speed of 220 r/min and the material moisture content of 35%.Under the optimized conditions,the product with higher gelatinization(86.72%),lower glycemic index(63.21),high rehydration rate(305%)and high sensory score(93 points)was obtained.【Conclusion】The process conditions have significant effects on the physicochemical property and eating quality of instant porridge,and their change law provides a theoretical basis for the development of other related products.